The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Takashi Hayashi - One of the best experts on this subject based on the ideXlab platform.
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supramolecular dimerization of a hexameric Hemoprotein via multiple pyrene pyrene interactions
Journal of Porphyrins and Phthalocyanines, 2020Co-Authors: Koji Oohora, Tsuyoshi Mashima, Shota Hirayama, Takashi HayashiAbstract:Protein assemblies are being investigated as a new-class of biomaterials. A supramolecular assembly of a mutant hexameric tyrosine coordinated Hemoprotein (HTHP) modified with a pyrene derivative i...
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Construction of a Hexameric Hemoprotein Sheet and Direct Observation of Dynamic Processes of Its Formation
Chemistry Letters, 2020Co-Authors: Koji Oohora, Shota Hirayama, Takayuki Uchihashi, Takashi HayashiAbstract:A two-dimensional sheet assembly of a hexameric Hemoprotein was constructed. A single cysteine residue was introduced onto each subunit surface in the hexameric Hemoprotein and modified with a male...
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Hemoproteins Reconstituted with Artificial Metal Complexes as Biohybrid Catalysts
Accounts of chemical research, 2019Co-Authors: Koji Oohora, Akira Onoda, Takashi HayashiAbstract:ConspectusIn nature, heme cofactor-containing proteins participate not only in electron transfer and O2 storage and transport but also in biosynthesis and degradation. The simplest and representative cofactor, heme b, is bound within the heme pocket via noncovalent interaction in many Hemoproteins, suggesting that the cofactor is removable from the protein, leaving a unique cavity. Since the cavity functions as a coordination sphere for heme, it is of particular interest to investigate replacement of native heme with an artificial metal complex, because the substituted metal complex will be stabilized in the heme pocket while providing alternative chemical properties. Thus, cofactor substitution has great potential for engineering of Hemoproteins with alternative functions. For these studies, myoglobin has been a focus of our investigations, because it is a well-known oxygen storage Hemoprotein. However, the heme pocket of myoglobin has been only arranged for stabilizing the heme-bound dioxygen, so the st...
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arginine residues provide a multivalent effect for cellular uptake of a Hemoprotein assembly
Chemistry Letters, 2019Co-Authors: Hiroaki Kitagishi, Koji Oohora, Ryota Kajihara, Misa Jiromaru, Takashi HayashiAbstract:Cellular uptake of rigid and flexible supramolecular Hemoprotein assemblies formed by cytochrome b562 was investigated. Multivalent cell-penetrating tags on the protein surfaces of the assemblies i...
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substitution of an amino acid residue axially coordinating to the heme molecule in hexameric tyrosine coordinated Hemoprotein to enhance peroxidase activity
Journal of Porphyrins and Phthalocyanines, 2017Co-Authors: Tsuyoshi Mashima, Koji Oohora, Takashi HayashiAbstract:To convert an originally tyrosine-coordinated heme to histidine-coordinated heme in hexameric tyrosine-coordinated Hemoprotein, HTHP, Tyr45, a residue coordinating to the heme cofactor, and Arg25 located in the distal site are replaced with Phe45 and His25, respectively in each of the subunits of the protein. The obtained HTHP mutant (HTHPR25H/Y45F) was characterized by SDS-PAGE, ESI-TOF MS, dynamic light scattering measurements and size exclusion chromatography. These analyses indicate that HTHPR25H/Y45F maintains its stable hexameric structure with the altered ligation of each of the heme cofactors. Comparison of UV-vis absorption spectra of the ferric-, ferrous-, CO- and CN-forms of HTHPR25H/Y45F with those of several well-known His-ligated Hemoproteins indicates that heme is coordinated by the His25 residue. The reaction of HTHPR25H/Y45F with cumene hydroperoxide produces both cumyl alcohol and acetophenone in a 2.3:1 ratio, indicating that heterolytic O–O bond cleavage dominantly occurs to form the t...
Koji Oohora - One of the best experts on this subject based on the ideXlab platform.
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supramolecular dimerization of a hexameric Hemoprotein via multiple pyrene pyrene interactions
Journal of Porphyrins and Phthalocyanines, 2020Co-Authors: Koji Oohora, Tsuyoshi Mashima, Shota Hirayama, Takashi HayashiAbstract:Protein assemblies are being investigated as a new-class of biomaterials. A supramolecular assembly of a mutant hexameric tyrosine coordinated Hemoprotein (HTHP) modified with a pyrene derivative i...
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Construction of a Hexameric Hemoprotein Sheet and Direct Observation of Dynamic Processes of Its Formation
Chemistry Letters, 2020Co-Authors: Koji Oohora, Shota Hirayama, Takayuki Uchihashi, Takashi HayashiAbstract:A two-dimensional sheet assembly of a hexameric Hemoprotein was constructed. A single cysteine residue was introduced onto each subunit surface in the hexameric Hemoprotein and modified with a male...
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Hemoproteins Reconstituted with Artificial Metal Complexes as Biohybrid Catalysts
Accounts of chemical research, 2019Co-Authors: Koji Oohora, Akira Onoda, Takashi HayashiAbstract:ConspectusIn nature, heme cofactor-containing proteins participate not only in electron transfer and O2 storage and transport but also in biosynthesis and degradation. The simplest and representative cofactor, heme b, is bound within the heme pocket via noncovalent interaction in many Hemoproteins, suggesting that the cofactor is removable from the protein, leaving a unique cavity. Since the cavity functions as a coordination sphere for heme, it is of particular interest to investigate replacement of native heme with an artificial metal complex, because the substituted metal complex will be stabilized in the heme pocket while providing alternative chemical properties. Thus, cofactor substitution has great potential for engineering of Hemoproteins with alternative functions. For these studies, myoglobin has been a focus of our investigations, because it is a well-known oxygen storage Hemoprotein. However, the heme pocket of myoglobin has been only arranged for stabilizing the heme-bound dioxygen, so the st...
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arginine residues provide a multivalent effect for cellular uptake of a Hemoprotein assembly
Chemistry Letters, 2019Co-Authors: Hiroaki Kitagishi, Koji Oohora, Ryota Kajihara, Misa Jiromaru, Takashi HayashiAbstract:Cellular uptake of rigid and flexible supramolecular Hemoprotein assemblies formed by cytochrome b562 was investigated. Multivalent cell-penetrating tags on the protein surfaces of the assemblies i...
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substitution of an amino acid residue axially coordinating to the heme molecule in hexameric tyrosine coordinated Hemoprotein to enhance peroxidase activity
Journal of Porphyrins and Phthalocyanines, 2017Co-Authors: Tsuyoshi Mashima, Koji Oohora, Takashi HayashiAbstract:To convert an originally tyrosine-coordinated heme to histidine-coordinated heme in hexameric tyrosine-coordinated Hemoprotein, HTHP, Tyr45, a residue coordinating to the heme cofactor, and Arg25 located in the distal site are replaced with Phe45 and His25, respectively in each of the subunits of the protein. The obtained HTHP mutant (HTHPR25H/Y45F) was characterized by SDS-PAGE, ESI-TOF MS, dynamic light scattering measurements and size exclusion chromatography. These analyses indicate that HTHPR25H/Y45F maintains its stable hexameric structure with the altered ligation of each of the heme cofactors. Comparison of UV-vis absorption spectra of the ferric-, ferrous-, CO- and CN-forms of HTHPR25H/Y45F with those of several well-known His-ligated Hemoproteins indicates that heme is coordinated by the His25 residue. The reaction of HTHPR25H/Y45F with cumene hydroperoxide produces both cumyl alcohol and acetophenone in a 2.3:1 ratio, indicating that heterolytic O–O bond cleavage dominantly occurs to form the t...
Hiroaki Kitagishi - One of the best experts on this subject based on the ideXlab platform.
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arginine residues provide a multivalent effect for cellular uptake of a Hemoprotein assembly
Chemistry Letters, 2019Co-Authors: Hiroaki Kitagishi, Koji Oohora, Ryota Kajihara, Misa Jiromaru, Takashi HayashiAbstract:Cellular uptake of rigid and flexible supramolecular Hemoprotein assemblies formed by cytochrome b562 was investigated. Multivalent cell-penetrating tags on the protein surfaces of the assemblies i...
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Supramolecular Hemoprotein Linear Assembly by Successive Interprotein Heme−Heme Pocket Interactions
Journal of the American Chemical Society, 2007Co-Authors: Hiroaki Kitagishi, Takashi Matsuo, Koji Oohora, Hiroyasu Yamaguchi, Hideaki Sato, And Akira Harada, Takashi HayashiAbstract:We demonstrate a new strategy for the construction of supramolecular Hemoprotein assemblies. A synthetic heme was selectively introduced onto the surface Cys residue of the cytochrome b562 single mutant (H63C) through a thioether bond. After removal of the native heme of the H63C mutant by acid denaturation followed by neutralization, the externally attached heme on the apoprotein surface was inserted into the vacant heme pocket of the other apoprotein. Therefore, the interprotein heme−heme pocket interaction produces a unique submicrometer-sized linear Hemoprotein fiber, determined by size exclusion chromatography and atomic force microscopy. This methodology should be widely applicable to the creation of new nanobiomaterials based on a functional Hemoprotein.
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supramolecular Hemoprotein linear assembly by successive interprotein heme heme pocket interactions
Journal of the American Chemical Society, 2007Co-Authors: Hiroaki Kitagishi, Takashi Matsuo, Koji Oohora, Hiroyasu Yamaguchi, Hideaki Sato, And Akira Harada, Takashi HayashiAbstract:We demonstrate a new strategy for the construction of supramolecular Hemoprotein assemblies. A synthetic heme was selectively introduced onto the surface Cys residue of the cytochrome b562 single mutant (H63C) through a thioether bond. After removal of the native heme of the H63C mutant by acid denaturation followed by neutralization, the externally attached heme on the apoprotein surface was inserted into the vacant heme pocket of the other apoprotein. Therefore, the interprotein heme−heme pocket interaction produces a unique submicrometer-sized linear Hemoprotein fiber, determined by size exclusion chromatography and atomic force microscopy. This methodology should be widely applicable to the creation of new nanobiomaterials based on a functional Hemoprotein.
Akira Onoda - One of the best experts on this subject based on the ideXlab platform.
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Hemoproteins Reconstituted with Artificial Metal Complexes as Biohybrid Catalysts
Accounts of chemical research, 2019Co-Authors: Koji Oohora, Akira Onoda, Takashi HayashiAbstract:ConspectusIn nature, heme cofactor-containing proteins participate not only in electron transfer and O2 storage and transport but also in biosynthesis and degradation. The simplest and representative cofactor, heme b, is bound within the heme pocket via noncovalent interaction in many Hemoproteins, suggesting that the cofactor is removable from the protein, leaving a unique cavity. Since the cavity functions as a coordination sphere for heme, it is of particular interest to investigate replacement of native heme with an artificial metal complex, because the substituted metal complex will be stabilized in the heme pocket while providing alternative chemical properties. Thus, cofactor substitution has great potential for engineering of Hemoproteins with alternative functions. For these studies, myoglobin has been a focus of our investigations, because it is a well-known oxygen storage Hemoprotein. However, the heme pocket of myoglobin has been only arranged for stabilizing the heme-bound dioxygen, so the st...
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Supramolecular assembling systems formed by heme–heme pocket interactions in Hemoproteins
Chemical communications (Cambridge England), 2012Co-Authors: Koji Oohora, Akira Onoda, Takashi HayashiAbstract:A native protein in a biological system spontaneously produces large and elegant assemblies via self-assembly or assembly with various biomolecules which provide non-covalent interactions. In this context, the protein plays a key role in construction of a unique supramolecular structure operating as a functional system. Our group has recently highlighted the structure and function of Hemoproteins reconstituted with artificially created heme analogs. The heme molecule is a replaceable cofactor of several Hemoproteins. Here, we focus on the successive supramolecular protein assemblies driven by heme–heme pocket interactions to afford various examples of protein fibers, networks and three-dimensional clusters in which an artificial heme moiety is introduced onto the surface of a Hemoprotein via covalent linkage and the native heme cofactor is removed from the heme pocket. This strategy is found to be useful for constructing hybrid materials with an electrode or with nanoparticles. The new systems described herein are expected to lead to the generation of various biomaterials with functions and characteristic physicochemical properties similar to those of Hemoproteins.
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Fibrous supramolecular Hemoprotein assemblies connected with synthetic heme dimer and apoHemoprotein dimer.
Chemistry & biodiversity, 2012Co-Authors: Akira Onoda, Koji Oohora, Akinori Takahashi, Yoshitaka Onuma, Takashi HayashiAbstract:Supramolecular Hemoprotein assemblies via heme-heme pocket interaction were prepared by synthetic heme dimers containing a linker with charged amino acids and apoHemoprotein disulfide dimers. The mixture of the negatively charged heme dimer and the apomyoglobin dimer provides heterotropic fibrous Hemoprotein assemblies, which were characterized by size-exclusion chromatography (SEC) and atomic force microscopy (AFM).
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Supramolecular Hemoprotein–gold nanoparticle conjugates
Chemical communications (Cambridge England), 2010Co-Authors: Akira Onoda, Yuichi Ueya, Taiki Sakamoto, T. Uematsu, Takashi HayashiAbstract:Interaction of apoHemoprotein with a covalently immobilized heme moiety onto a gold nanoparticle surface resulted in supramolecular Hemoprotein–gold nanoparticle conjugates. The addition of an apoHemoprotein dimer further led to a densely-packed Hemoprotein–gold nanoparticle assembly, which was visualized by TEM and AFM measurements.
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Supramolecular Hemoprotein-gold nanoparticle conjugates.
Chemical communications (Cambridge England), 2010Co-Authors: Akira Onoda, Yuichi Ueya, Taiki Sakamoto, T. Uematsu, Takashi HayashiAbstract:Interaction of apoHemoprotein with a covalently immobilized heme moiety onto a gold nanoparticle surface resulted in supramolecular Hemoprotein-gold nanoparticle conjugates. The addition of an apoHemoprotein dimer further led to a densely-packed Hemoprotein-gold nanoparticle assembly, which was visualized by TEM and AFM measurements.
And Akira Harada - One of the best experts on this subject based on the ideXlab platform.
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Supramolecular Hemoprotein Linear Assembly by Successive Interprotein Heme−Heme Pocket Interactions
Journal of the American Chemical Society, 2007Co-Authors: Hiroaki Kitagishi, Takashi Matsuo, Koji Oohora, Hiroyasu Yamaguchi, Hideaki Sato, And Akira Harada, Takashi HayashiAbstract:We demonstrate a new strategy for the construction of supramolecular Hemoprotein assemblies. A synthetic heme was selectively introduced onto the surface Cys residue of the cytochrome b562 single mutant (H63C) through a thioether bond. After removal of the native heme of the H63C mutant by acid denaturation followed by neutralization, the externally attached heme on the apoprotein surface was inserted into the vacant heme pocket of the other apoprotein. Therefore, the interprotein heme−heme pocket interaction produces a unique submicrometer-sized linear Hemoprotein fiber, determined by size exclusion chromatography and atomic force microscopy. This methodology should be widely applicable to the creation of new nanobiomaterials based on a functional Hemoprotein.
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supramolecular Hemoprotein linear assembly by successive interprotein heme heme pocket interactions
Journal of the American Chemical Society, 2007Co-Authors: Hiroaki Kitagishi, Takashi Matsuo, Koji Oohora, Hiroyasu Yamaguchi, Hideaki Sato, And Akira Harada, Takashi HayashiAbstract:We demonstrate a new strategy for the construction of supramolecular Hemoprotein assemblies. A synthetic heme was selectively introduced onto the surface Cys residue of the cytochrome b562 single mutant (H63C) through a thioether bond. After removal of the native heme of the H63C mutant by acid denaturation followed by neutralization, the externally attached heme on the apoprotein surface was inserted into the vacant heme pocket of the other apoprotein. Therefore, the interprotein heme−heme pocket interaction produces a unique submicrometer-sized linear Hemoprotein fiber, determined by size exclusion chromatography and atomic force microscopy. This methodology should be widely applicable to the creation of new nanobiomaterials based on a functional Hemoprotein.